• Journal of Welding and Joining
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• v.31 no.6
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• pp.58-64
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• 2013

Several joining methods involving resistance welding, laser welding, ultrasonic welding and mechanical joining are currently applied in manufacturing lithium-ion batteries. Cu and Al alloys are used for tab and bus bar materials, and laser welding characteristics for these alloys were investigated with similar and dissimilar material combinations in this study. The base materials used were Al 1050 and oxygen-free Cu 1020P alloys, and a disk laser was used with a continuous wave mode. In bead-on-plate welding of both alloys, the joint strength was higher than the strength of O tempered base material. In overlap welding, the effect of welding parameters on the tensile shear strength and bead shape was evaluated. Tensile shear strength of overlap welded joint was affected by interfacial bead width and weld defect formation. The tensile-shear specimen was fractured at the heat affected zone by selecting proper laser welding parameters.

• Journal of Radiation Protection and Research
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• v.11 no.1
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• pp.51-56
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• 1986

It is important to measure and protect from the radiation space dose and induced activity at the high energy medical linear accelerator facilities. These are to consider the additional risk to patients undergoing treatment, machine operators and staff members. Measurements of the space dose distribution and induced radioactivity at the 18 MeV medical linear accelerator facility in the Yonsei Cancer Center. 1. Exposure space dose for 300 rads monitor doses of 18 MeV electron are measured as 50 mR at 1 meter from patients. 2. Exposure space dose for 300 rads monitor doses of 10 MV X-ray are detected as 350 mR at 1 meter from phantom. 3. Induced radioactivity by photonuclear reaction was measured as 0.65 mR/hr from collimater after 30 Gy(3,000 rads) irradiated. 4. Analyzing the decay curves and energy spectrum of induced radioactivity, detected a few materials to be activated by photoneutron reaction, $^{65}Cu({\gamma}{\cdot}n)\;^{64}Cu,\;^{186}W({\gamma}{\cdot}n)\;^{185}W,\;^{181}Ta({\gamma}{\cdot}n)\;^{180}Ta,\;^{199}Au({\gamma}{\cdot}n)\;^{198}Au$.

• Journal of Life Science
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• v.22 no.10
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• pp.1330-1338
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• 2012

Solvent extracts of Theobroma cacao L. (TCL) were investigated for anti-oxidative and anti-inflammatory effects in order to consider TCL as a functional ingredient for cosmetic products. TCL(A) extract was fractioned according to polarity with $CHCl_3$, EtOAc, n-BuOH, and water. Following TCL(A) fractionation, the electron-donating ability of the n-BuOH and EtOAc solvent fractions (each 100 ${\mu}g/ml$) was about 76.2% and 53.9%, respectively. The superoxide anion radical inhibitory effect of the n-BuOH and EtOAc solvent fractions (each 50 ${\mu}g/ml$) was about 76.09% and 51.4%, respectively. Results of lipid oxidation showed that $Fe^{2+}$ had a greater chelating effect than $Cu^{2+}$. The $Fe^{2+}$ chelating effect of the EtOAc solvent fraction (50 ${\mu}g/ml$) was about 64%. Hyaluronidase inhibition related to the anti-inflammatory effect was 53.0% with EtOAc at 100 ${\mu}g/ml$, while the lipoxygenase inhibitory effect was about 51.32% at 10 ${\mu}g/ml$. The anti-inflammatory activity in the EtOAc fraction inhibited the generation of nitric oxide. Results also showed that iNOS protein expression increased in RAW264.7 cells. In contrast, at 100 ${\mu}g/ml$ EtOAc, iNOS and COX-2 protein expression significantly decreased in LPS-stimulated RAW 264.7 cells.

• Resources Recycling
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• v.29 no.2
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• pp.69-77
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• 2020

With rapid increasing production and installation, recycling of photovoltaic modules has become the main issue. According to the research, the accumulation of waste modules will reach to 8600 tons in 2030. Moreover, Crystalline-silicon (c-Si) Photovoltaic modules account for more than 90% of the waste. C-Si PV modules contain 1.3% of weight of photovoltaic ribbon inside which contains the most of lead, tin and copper in the PV modules, which would cause environmental and humility problem. This study provided a valuable metal separation process for PV ribbons. Ribbons content 82.1% of Cu, 8.9% of Sn, 5.2% of Pb, and 3.1% of Ag. All of them were leached by 3M of hydrochloric acid in the optimal condition. Ag was halogenated to AgCl and precipitated. Cu ion was extracted and separated from Pb and Sn by Lix984N then stripped by 3M H2SO4. The effect of the optimal parameters of extraction was also studied in this essay. The maximum extraction efficiency of Cu ion was 99.64%. The separation condition of Pb and Sn were obtained by adjusting the pH value to 4 thought ammonia to precipitate and separate Pb and Sn. The recovery of Pb and Sn can reach 99%.

• Economic and Environmental Geology
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• v.35 no.3
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• pp.211-220
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• 2002

The Xiaoxinancha Cu-Au deposit in the Jilin province, located in NNE 800 km of Beijing, is hosted by diorite. The ore mineralization of Xiaoxinancha Cu-Au deposit show a stockwork occurrence that is concentrated on the potassic and phyllic alteration zones. The Xiaoxinancha Cu-Au deposit in the south is being mined with its reserves grading 0.8% Cu, 3.64 g/t Au and 16.8 g/t Ag and in the north, grading 0.63% Cu, 3.80 g/t Au and 6.8 glt Ag. The alteration assemblage occurs as a supergene blanket over deposit. Hydrothermal alteration at the Xiaoxinancha Cu-Au deposit is centered about the stock and was extensively related to the emplacement of the stock. Early hydrothermal alteration was dominantly potassic and followed by propylitic alteration. Chalcocite, often associated with hematite, account for the ore-grade copper, while chalcopyrite, bornite, quartz, epidote, chlorite and calcite constitute the typical gangue assemblage. Other minor opaque phases include pyrite, marcasite, native gold, electrum, hessite, hedleyite, volynskite, galenobismutite, covellite and goethite. Fluid inclusion data indicate that the formation of this porphyry copper deposit is thought to be a result of cooling followed by mixing with dilute and cooler meteoric water with time. In stage II vein, early boiling occurred at 497$^{\circ}$C was succeeded by the occurrence of halite-bearing type III fluid inclusion with homogenization temperature as much as 100$^{\circ}$C lower. The salinities of type 1II fluid inclusion in stage II vein are 54.3 to 66.9 wt.% NaCI + KCI equiv. at 383$^{\circ}$ to 495$^{\circ}$C, indicating the formation depth less than 1 km. Type I cupriferous fluids in stage III vein have the homogenization temperatures and salinity of 168$^{\circ}$ to 365$^{\circ}$C and 1.1 to 9.0 wt.% NaCI equiv. These fluid inclusions in stage III veins were trapped in quartz veins containing highly fractured breccia, indicating the predominance of boiling evidence. This corresponds to hydrostatic pressure of 50 to 80 bars. The $\delta$$^{34}S$ value of sulfide minerals increase slightly with paragenetic time and yield calculated $\delta$$^{34}S_{H2S}$ values of 0.8 to 3.7$\textperthousand$. There is no mineralogical evidence that fugacity of oxygen decreased, and it is thought that the oxygen fugacity of the mineralizing fluids have been buffered through reaction with magnetite. We interpreted the range of the calculated $\delta$$^{34}S_{H2S}$ values for sulfides to represent the incorporation of sulfur from two sources into the Xiaoxinancha Cu-Au hydrothermal fluids: (1) an isotopically light source with a $\delta$$^{34}S$ value of I to 2$\textperthousand$, probably a Mesozoic granitoid related to the ore mineralization. We can infer from the fact that diorite as the host rock in the Xiaoxinancha Cu-Au deposit area intruded plagiogranite; (2) an isotopically heavier source with a $\delta$$^{34}S$ value of > 4.0$\textperthousand$, probably the local porphyry.

• Journal of environmental and Sanitary engineering
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• v.3 no.2 s.5
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• pp.91-98
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• 1988

This study was carried out to investigate the Pollution of heavy metals in Soil, collected from the 50 sampling sites in 1986. The results were as follows; 1. In the average contents of Cd, the highest value was 0.33mg/kg in the Industrial area, the lowest value was 0.06 mg/kg in the Greenbelt and 0.10-0.22mg/kg in the other areas. 2. In the average contents of Cu, the highest value was 33.46mg/kg in the Industrial area, the lawest value was 3.79mg/kg in the Greenbelt and 4.69-12.21mg/kg in the other areas. 3. In the average contents of As, the highest value was 1.80mg kg in the Residential area, the lowest value was 0.43mg/kg in the Greenbelt and 0.64-1.65mg/kg in the other areas. 4. In the average contents of Zn, the highest value was 29.84mg/kg in the out wall of Seoul, the lowest value was 17.32mg/kg in the Greenbelt and 19.62-26.71mg/kg in the other areas. 5. In the average contents of Pb, the highest value was 17.09mg/kg in the Industrial area, the lowest value was 5.21mg/kg in the Reclamated waste and 5.67 -14.10mg/kg in the other areas. 6. Distribution of Heavy metals was Zn>Cu>Pb>As>Cd and the relations of Zn-Cd, Pb-Cd, Pb-Cu, Pb-Zn were shown the correlation significantly (P< 0.01).

• BMB Reports
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• v.28 no.3
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• pp.254-260
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• 1995

Cytochrome oxidase was purified from bovine-heart mitochondria and its enzymatic properties were examined. The purified cytochrome oxidase was identified by its absorption spectrum and chromatogram through gel filtration. The specific activity, purification degree and yield of purified cytochrome oxidase were 18 nmol/mg/ml/min, 24.83 fold and 0.93%, respectively. The activity of the enzyme assayed by a ferrocytochrome $c-O_2$ system was optimized at $25^{\circ}C$ and pH 6.5. Examining the effect of nonionic detergents established that cytochrome oxidase was deactivated by Triton X-100. The oxidase was activated by Tween 80 and deactivated by Tween 20. The Michaelis constant and maximum velocity of the oxidase for ferrocytochrome c were 0.032~0.044 mM and 0.019~0.021 mM/min, respectively. After adaption to basal diet for a week, experimental diets containing 6 mg Cu/kg, or zero mg Cu/kg, or 12 mg Cu/kg were fed to a control group, a copper-free group and a copper-rich group of Sprague-Dawley rats, respectively, for 4 weeks. The specific activities assayed for the ferrocytochrome $c-O_2$ system of isolated cytochrome oxidase from the rat liver of control, copper-free, and copper-rich group were 1.00, 1.19, and 0.878 nmol/mg/ml/min, respectively. Their degrees of purification were 11.38, 10.82 and 8.78 fold, respectively. The specific activities for liver and heart mitochondrial cytochrome oxidase of copper-free/copper-rich groups assayed using the ferrocytochrome $c-O_2$ system were 81.4% and 96.4%/64.1% and 61.1%, respectively, compared with those of the control.

• Journal of Nutrition and Health
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• v.26 no.1
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• pp.89-97
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• 1993

This study was carried out to estimate the relationship between dietary intake, blood level, and urinary excretion of minerals and blood pressure in 30 healthy adults living in rural area of Korea(12 males and 18 females). Analysis for the nutritional status of the subjects were performed by 3-day dietary intake record, duplicated diet collection, 24-hour urine collection, and venous blood sampling before measuring blood pressure. The mean blood pressure of subjects was 117.50/80.83mmHg in males and 110.00/73.89mmHg in females. The mean daily intakes of Na, K, Ca, P, Mg, Fe, Cu, Zn estimated for 3 days were 199.97mEq, 49.56mEq, 452.50mg, 725.57mg, 240.40mg, 12.48mg, 3.41mg, 8.28mg, respectively. The serum concentration of Na, K, Ca, P, Mg, Fe, Cu, Zn were 139.83mEq/dl, 4.06mEq/dl, 8.86mg/dl, 3.28mg/dl, 2.13mg/dl, 0.12mg/dl, 0.12mg/dl, 0.14mg/dl, respectively. The 24-hour urinary excretions of Na, K, Ca, p, Mg, Fe, Cu, Zn estimated for 169.60mEq, 39.37mEq, 80.40mg, 398.97mg, 64.77mg, 0.21mg, 0.07mg, 0.29mg, respectively. No significant correlation was found between dietary intake, serum concentration, and urinary excretion of minerals and blood pressure. But, the serum Ca/Mg ratio showed negative correlation with the systolic and diastolic blood pressure at the level of significance of 5%. The study verifies the need for more systematic studies on interrelationship among minerals and mineral requirements in normotensive and hypertensive subjects.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.3
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• pp.388-394
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• 2001

This study was conducted ton investigate the mineral contents of commercial baby foods. Samples were classified into 4 groups; powdered formula, baby juice product (domestic), juice and paste products (imported) and soymilk-based formula. We analyzed Ca, P, Mg, Na, K, Fe, Cu, Zn contents by atomic absorption spectrophotometer after dry-ashing. The difference of analyzed value versus labeled value and Ca/P ratio of analyzed value were calculated. The difference (%) of analyzed value on the labeled value was Ca: 98.6, P: 121.8, Mg: 146.1, Na: 87.4, K: 104.3, Fe: 104.8, Cu: 120.2, Zn: 109.8 in powdered formula, Mg showed the highest difference among the elements. The Ca/P ratio of powdered formula was 1.41 (1.70-1.99). Baby juice products (domestic) were fortified Ca, Fe and the difference (%) of analyzed value on labeled value of Ca and Fe contents was 131.8, 110.2, respectively. The Ca/P ratio of these was 2.36 (1.64-3.71). Differently the domestic products, imported juice and paste products were not fortified Ca, Fe and its Ca/P ratio was 0.38(0.14-0.59). The difference (%) of analyzed value on the labeled value was Ca: 110.2, Mg: 179.5, Na: 83.7, K: 87.8, Cu: 107.8, Fe: 219.8, Zn: 100.5, P: 126.6 in soymilk-based formula, Fe showed the highest difference among the elements. The Ca/P ratio of soymilk-based formula was 1.17 (1.04-0.39).

• Journal of the Korean Chemical Society
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• v.30 no.2
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• pp.201-206
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• 1986

A new analytical reagent N-benzylisonitrosoacetylacetone imine (H-IAA-N-Bz) has been synthesized and identified its structure by IR, NMR and mass spectra. H-IAA-N-Bz forms a copper chloroform-soluble complex in a basic aqueous solution (pH = 7.0∼10.0). The other optimum conditions for the spectrophotometric study of the copper complex have been determined at 420nm. Beer's law is obeyed below the concentration of 64$\mu$g of copper per 10ml of chloroform. The composition of the copper complex has been found to be $Cu(IAA-N-Bz)_2$ and the over-all stability constant is calculated to be $8.55 {\times} 10^6$. The molar absorption coefficient, $\varepsilon$ of the $Cu-(IAA-N-Bz)_2 $complex is 3500l/$cm{\cdot}mol$.